It s not the case of re-selling your PC or your iPhone!!!!
It is not the case of re-selling your copy of OSX!!!!
It is not the case of installing your OSX on your privately used PC!!!
You can it and shout it out to the world what a technically savvy bloke you are.

Ask DELL or HP which OS they'd rather pre-install on their PCs. OSX of course.
Why don't they? BECAUSE APPLE REFUSES TO SELL THEM LICENSES